C22:0- and C24:0-dihydroceramides Confer Mixed Cytotoxicity in T-Cell Acute Lymphoblastic Leukemia Cell Lines
Figure 6
Effects of specific fatty acids on sphinganine + GT-11-induced dihydroceramide accumulation and cytotoxicity.
A) Effects of fatty acids on dihydroceramide levels. MOLT-4, COG-LL-317h, and COG-LL-332h, cell lines were treated with sphinganine (1 µM) + GT-11 (0.5 µM) supplemented with the indicated fatty acid (5 µM) for six hours and sphingolipids analyzed. Data are normalized to cells that received sphinganine + GT-11 without fatty acid supplementation and dihydroceramide levels plotted as fold change (Z-axis). Significant (P ≤ 0.05) fold change differences are indicated by asterisks (*). B) Effects of fatty acids on cytotoxicity. Cell lines were treated with sphinganine (0-4 µM) ± GT-11 (0.5 µM) and supplemented with C18:0-, C22:0- or C22:1-fatty acids (5 µM). Cytotoxicity assessed at +48 hours by DIMSCAN cytotoxicity assay. Data were normalized to controls and plotted as Survival Fraction (Y-axis). Error bar, SEM.